1. Field of the Invention
This invention relates generally to protective devices for avoiding impact damage to walls, cabinetry, furniture, chinaware and other objects, and more particularly to transparent self-attaching bumpers.
2. Prior Art
A great variety of bumpers is known for cushioning the impact of swinging doors (particularly including the corners of cabinet doors) and doorknobs, hinged table sections and other panels, rolling carts, and so forth, against walls and furniture. Such bumpers protect the moving surface as well as the stationary surface, and therefore--as an example--are also used for preventing damage to toilet seats when they bump against water closets.
All of these applications, and myriad others, are well known--and have been the object of many commercial "bumper" products. The thrust of design in these products has been to provide bumpers that are sturdy, attachable to the vulnerable surface to be protected (or to the hard surface to be guarded) in a variety of ways, and reasonably attractive.
This last objective has given rise to bumpers in a great variety of shapes, sizes, expensive brushed-metal finishes, decorator colors, and so forth--but by and large has not been satisfied. Bumpers are almost intrinsically unattractive, for several reasons. They are practically by definition something "added on" to a home or office after the decor elements have been settled. They are also conspicuous by virtue of being small, spike-shaped or stubby or knobby objects secured to planar or large-contour surfaces. Attachment is often by screws, which are relatively quite large in relation to the size of each bumper itself.
Even the most esthetic of bumpers, however, are unattractive because they simply do not match the color--or the complex pattern--of the protected or guarded surfaces. They thus appear, at the very least, as non-color-matched "spots" on the wall, wallpaper, or other surface.
Turning to a different field, certain household protective functions have been served by generally transparent articles such as transparent escutcheons for electrical switches. The purpose of such articles, however, has not been to protect against damage due to impacts, but rather generally to protect against soiling of the wall surface near an electrical switch by the oily or dirty hands of users.
Moreover the problem of inconspicuous attachment of such devices is minimized--since the switch itself and its opaque switchplate, behind the transparent escutcheons, are themselves conspicuous interferences with the decor. Too, there is very little added annoyance produced by the means of attachment of the escutcheons to the switchplates--often using the same screws that attach the switchplates to the junction boxes.
In an even more remote field, U.S. Pat. No. 3,687,792 to Charles Ruff discloses a decorative trim strip for automobiles and the like. Ruff's trim strip is composed of a colored ribbon that is coextruded with a generally transparent, colorless plastic bar of trapezoidal cross-section. The ribbon is cemented to the surface to be decorated, and the angles of the plastic bar--along its edges that are elevated above the colored ribbon--are such as to trap any light entering the plastic bar.
Regardless of the angle of entry, in Ruff's invention, light is directed to the colored ribbon; in addition, only light reflected from the colored ribbon can escape the transparent plastic bar. Thus the bar, although actually colorless, appears to have the color of the underlying ribbon. The objective of Ruff's invention is to provide a trim strip that appears to have any one of a great variety of different colors even though it is only the ribbon that is actually colored. Thus the Ruff device is deliberately designed to distort the passage of light in and out of the trim strip.
Now it will be plain that if a piece of Ruff's trim strip were glued over a wall--such as a solid-color wall or a patterned-wallpaper-covered wall--in a home or office, the trim strip would be very conspicuous. It would thus fail to satisfy the needs suggested earlier.
In principle, one might propose to separate the transparent plastic bar that forms the upper portion of Ruff's trim strip from the ribbon portion. One might then propose to use only the plastic bar, in household and office applications such as outlined above.
Ruff, it must be emphasized, suggests no such possibility. His invention is in an entirely different field, and exists for an entirely different purpose, than to guard household or office surfaces inconspicuously, and he does not suggest separating the two components of his invention for any purpose. Without such a suggestion it would not be obvious to make such a modification. Even if this proposed modification of the Ruff invention were made, however, the resulting performance would be quite unsatisfactory for the purposes discussed in this document.
In the case of a uniformly colored wall, the area covered by the plastic bar would have a conspicuously different apparent illumination level than the rest of the wall. This would be a natural consequence of the deliberate design of Ruff's bar to trap all light entering at all possible entry angles and to direct such light to the underlying surface. The surface covered by the plastic bar would appear conspicuously brighter than the surrounding surface.
In the case of a patterned wall surface, dislocations would appear in the image of the pattern as seen through the plastic bar. These dislocations would be due to the abrupt differences in refraction along the distinctly angled edges of the plastic bar, well elevated in front of the wall surface.
To my knowledge there has never been any effort to combine the teachings from these various fields.